As it is known, respiratory circuits, which are used to interface in a flexible manner the tracheal or tracheostomy tube of a patient with a ventilation system, comprise filter and HME (Heat Moisture Exchanger) devices in order to ensure that the quality, temperature and humidity of the air inhaled by the patient are such that they have no negative effects on the patient. HME devices are suitable to retain water vapour coming from the air exhaled by the patient and to use it to humidify the air coming from the ventilation system and which will be inhaled by the patient.
A drawback that can occur during use of respiratory circuits concerns the formation of condensation coming from humidity in the air exhaled by the patient. In fact, the air exhaled is at a higher temperature and when it reaches the filter and/or HME device, it encounters a lower temperature which can cause the formation of condensation of the water vapour with which it is saturated.
As may be apparent, the formation of this condensation can compromise correct operation of the filter and/or HME device, at least partially obstructing the passage of air, with the consequence that this filter and/or HME device must be replaced, with the problems in terms of cost and practicality that this implies.